Telephone-receiver



C. KRAFT.

TELEPHONE HECEIVEH.

APPLICATION FILED JUNE25. i319.

Patented Feb. 17,1920.

TOR. Z

11/5 TTORNEY tliNI'IiED srarnsra'rnnr QFFICE.

01* NEJV YDRK, N. 1., ASSIGNOR OF ONE-HALF T0 L. STEUIAR'I GATTER, OF

NEW YORK, N. Y.

TELEPHONE-RECEIVELt.

Application filed J uzfe 25,

To a? whom z't may concern:

Pe it. known that I, ()Anr. KRAFT, a citizen of the United States, residing at New York,

in. the count of New York and State oi Mi invention relates es eciallv to the 50-- called watch-case type of telephone receiver .fy used in receiving sets for aircraft, tanks and headsets.

. of my device is to provide an improved means of receiving telephone coinniunication in that the construction of the device permits it to he inclosed in a fiat case and thereby fit closely to the ear and head and eliminate the air resistance obtaining with the use of the present type receiver.

A. further object of my invention is to provide an improved type of receiver for electrical communication of such constructioir'and size as to be adapted to the requirements of receiver sets for deaf persons whereby same can be readily anc easily grasped in the hand and is not as objection able in appearance when placed to the ear as the present type of receiver used for this purpose.

In the drawings illustrating a preferred embodiment of this invention Figure 1, is a plan View oi the out-side of the receiver in which A is the cap. B the diaphragm and l" the orifice. Fig. 2 is a side elevation of the complete receiver. A is the cap, C the case. l) and F. binding posts for electrical connect-ions. F 3 is an enlarged full cross sectional elevation. A is the cap. F the orifice, G a washer. B a metallic diaphragm and ll is a metallic thrcadedclanipinp; ring holding diaphragm B securely in cap A. The case G contains the magnetic circuit N, I which may be laminated or otherwise. Binding posts D and E are'con nected to coils O andl and when energized lines of force are set up and directed onto -the diaphragm through pole pieces NM. The insulation U is provided on coils, Q connects coils O and P, screws J and K hold, the i'nagnets and the coil in place. Adjustment of the airap is made by screwing; cap A on case S but any other type of Specification of Letters Patent.

Patented Feb. 1'3. 1920.

1919. Eerie No. soc e11.

adjustment may he used. Fig. t is a plan view with the cap and diaphragm removed. Fig. 5 is a sectional .lEW through plane T of Fig. *1 and with Fig. 6 illustrates other possibilities of magnetic circuits.

What I claim is f l. In a, telephone receiver a diaphragm adapted to be actuated by electro-magnets, said diaphragm being mounted and held at its periphery, the cores or polepieces of said electro-xnagnets being elliptical in cross-section, mounted, for the purpose of utilizip minimum space and reducing the depth or the receiver, so that the major or; ial plane of the elliptical"cross-section of the main portion of said core is parallel to the plane of the diaphragm but with. the ends of said cores or pole-pieces turned at right angles. to'the main portion thereof and toward the diaphragm, havingmounted on the main portion of said cores or pole-pieces magnet who of suitable characteristics for actuating the diaphragm means of the cores or pole-pieces when energized, "all mounted in a case substantially as and for the purposes hereinhefore set forth.

In a telephone receiver of the type described. the combination of a dis hra 'm 3 adapted to be actuated by elcctro-inagnets and mounted at its periphery, with cores or pole-pieces of rectangular cross-section. mounted, for the purpose of utilizing minimum space and reducing the depth of the receiver, so that the major axial plane of the rectangular cross-section of the main portion of said core is parallel to the plane of the diaphragm but with the ends of said cores or pole-pieces turned at ri ht angles to the mainportion thereof and toward the diaphragm, having magnet wire spools placed on the main portion of the said cores or pole-pieces, all mounted in a case substantially as'and for the purposes herein hefor. set forth.

In witness whereof I hereunto subscribe my name this 20 day of June A. 33-. 1919.

CARL KRAFT.

Witnesses:

Seamus T. Dtozzmmnn, SAME 

